Why is my male friend leaving me on read/delivered all of the sudden and how can I get him to stop doing this?

I have this male friend of mine who I also have a crush on.

I don't think he really likes me back or would like to open a relationship with me. I feel like I'm friend zoned by him. I could tell because he said he was not open to dating anyone and he would always try to push me away when I got flirty. I've come to terms that we would never be together but that burning desire seems to come up every so often.

We met on April of this year. We talked very frequently and he would always reply to me in an instant. Our conversations were long and fun and we would always call eachother.

That all stopped once we went back to school. He started acting distant to me and the conversations lost the joy and enthusiasm. He would often leave me on delivered for so many hours. And when we did get the time to talk he would text back with lazy responses and abbreviations. Our conversations became short and boring. I was always the one trying to put effort to contact him and make plans with him and start a conversation. It became nonreciprocal as I was the one putting in the effort to contact him while he would leave me on read and delivered for so long.

When we did see eachother during school he was usually caught up with his friends and barely came over to me to strike up a conversation or say hi. When we did talk it was short conversations. Everything was going so well between us. I never offended him or rubbed him the wrong way. And now , suddenly, everything has become sort of distant. Why had this happened and what can I do to bring back the relationship to how it was before?

Why is my male friend leaving me on read/delivered all of the sudden and how can I get him to stop doing this?
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